package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.UUID;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

     @Resource
     private ISeckillVoucherService seckillVoucherService;

     @Resource
     private RedisIdWorker redisIdWorker;

     @Resource
     private StringRedisTemplate stringRedisTemplate;




    @Override
    public Result seckillVoucher(Long voucherId) {

        //1.查询优惠券
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);

        //2.判断秒杀是否开始
        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒杀未开始");
        }

        //3.判断秒杀是否结束
        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已结束");
        }

        //4.判断库存是否充足
        if (seckillVoucher.getStock() < 1) {
            return Result.fail("库存不足");
        }



//        //一人一单，存入redis
//        String key = "user:" + UserHolder.getUser().getId() + ":order";
//        stringRedisTemplate.opsForSet().add(key, orderId + "");

        //一人一单
        Long userId = UserHolder.getUser().getId();

        //创建锁对象
        SimpleRedisLock lock = new SimpleRedisLock(
                "order:" + userId,
                stringRedisTemplate
        );

        //获取锁
        boolean isLock = lock.tryLock(1200);

        if (!isLock) {
            //获取锁失败
            return Result.fail("不允许重复下单");
        }

        try {
            //获取代理对象
            IVoucherOrderService o =(IVoucherOrderService) AopContext.currentProxy();
            //7.返回订单id
            return o.createVoucherorder(voucherId);
        }finally {
            lock.unlock();
        }

    }

    @Transactional
    public  Result createVoucherorder(Long voucherId){

        //一人一单
        Long userId = UserHolder.getUser().getId();


            //查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            if (count > 0) {
                return Result.fail("用户已购买过该优惠券");
            }

            //5.扣减库存
            //加上乐观锁CAS
            boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherId)
                    .gt("stock", 0)
                    .update();

            if (!success) {
                return Result.fail("库存不足");
            }
            //6.创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            //创建订单id，可以用redis生成全局唯一id。
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            //用户id
            voucherOrder.setUserId(UserHolder.getUser().getId());
            //优惠券id
            voucherOrder.setVoucherId(voucherId);

            //返回数据库
            save(voucherOrder);

            return Result.ok(orderId);
        }
}
